They (that's the group of hospitals he works for) want to obtain an archive for every image produced in the hospitals. And by every image, they mean every image. They (the group of hospitals he works for) already have PACS’essss (Preciousss… eh …Picture Archive and Communication Systems) for radiology and nuclear medicine. Now it’s about implementing an archive for all the other images: Endoscopy (fiberoptic tubes inserted into every natural, most of them yecchy, opening in your body), digital photos, pathology images and lots more. Including videos. And they (the group of hospitals he works for) want to be able to look at all these images in a viewer which can display several types of images simultaneously. Every clinician in even the darkest corners of the hospitals should be able to access images, subject to laws governing patient security. And they should be able to do it from the EPR (electronic patient record). They (the group of … oh bother) also consider migrating PACS images to the new archive, using it as a long time storage for radiology.

They want a VNA (Vendor Neutral Archive). Which for instance means that they should be able to access the images using widely different viewers, and not being locked to one single vendor. Another important aspect, in many ways the ultimate test of vendor neutrality, is what happens if they some time in the future want to replace the current VNA vendor with another one. In a VNA this should be easy, and especially not require copying images to yet another archive. This is important because migrating images is an expensive and very time consuming affair.

One example: In the PACS systems they have approximately 500 TB of image data, 6 million examinations, more than 100 million images. Now, copying 500 TB in itself shouldn't take that much time. But radiology images are more than bitmaps, they also store the context of the images, metadata, such as patient id, type of examination, the organ examined, details regarding how the images were acquired, sequence number if the image is part of a multi image study (CT, MRI…), and much, much more. Especially important are their connections to radiology information systems. Together, bitmaps and metadata constitute the image object, or as friends like to say: the DICOM object, after the standard covering storage of radiology images. Metadata is stored in so called DICOM tags. The standard specifies which tags should contain what information. However the standard also allows private tags, unofficial tags which may be used for whatever a vendor of radiology hardware and software would like to place there. And most vendors do exactly that. Which unfortunately makes DICOM objects from different vendors not 100% compatible, and complicates migration.

Migration images therefore involves more than just copying the bitmaps. Metadata must also be transferred, usually after some editing. (Although each DICOM object is one complete object, the objects are are usually splitted in storage, with the bitmaps stored as files, and the DICOM tags in a database). It has to be a tightly controlled process, they can’t risk connecting images to the wrong patient. All this takes time, at least several months. Additionally, despite all efforts, errors are bound to happen. It’s not funny, and it’s obviously not something one would want to do very often.

He went to Chicago last november, because he knows something about these things. And every year there is a huuuge radiology conference there, held by RSNA (Radiology Society of North America). It's THE RADIOLOGY CONFERENCE. Which means that every vendor of radiology equipment and software solutions who wants to sell lots of their things will be there. So he came, saw and talked to many people to help understanding what's possilble and how it could be done.

Now you know, tomorrow you most likely won’t bother. Just wait until pibbur tells you why he went to Baltimore, Phoenix, Atlanta and this autumn will be going to Boston.